Answered by Shaykh Muhammad ibn Adam al-Kawthari
Is it permitted to be a police officer in the West?
In the name of Allah, Most Compassionate, Most Merciful,
In principle, it would be permissible to work as a police office, rather, if the intention is to help and assist the oppressed, prevent crime and give people their just rights, it will be an act of virtue, provided one refrains from sins such as bribery, etc.
However, if becoming a police officer entails one to be involved in something that is contrary to Shariah, then it will not be permissible to take this occupation. If there are principles within the establishment that are against Islamic teachings, but one is able to avoid them, then it would be permissible to become an officer. We see Sikhs, for example, that they evade certain rules and principles, of which the concession of wearing a turban is well-known.
Therefore, the above is the criteria on which one must decide whether to take this profession. The ruling may change from one individual to another and from one country to another.
And Allah knows best
Muhammad ibn Adam al-Kawthari, UK